Antiaircraft sight



Nov. 8, 1932.` w. T. RlcKARDs 1,887,363

ANTIAIRCRAFT SIGHT Filed March 21, 1952 eli Patented Nov. 8, 1932 PATENT OFFICE WILLIAM 'I'. RICKARDS, 0F CHICAGO, ILLINOIS ANTIAIRCRAFT SIGHT Application Ied March 21, 1932. Serial No. 600,102.

My invention relates to gun sights for shooting at moving targets, and is particularly adapted to use against airplanes, where the target is usually traveling across or at 5 an angle to the straightaway either horizontally or at an ascending or descending angle thereto.

The primary object of the invention is to remove so far as is practicable the element of approximation or guesswork by the gunner, providing mechanism for adjusting the sight to the proper lead on the moving target and leaving only to the gunner the estimation of target speed, the determination of the angle to the horizontal and the shifting of the sight to accord with graduations thereon corresponding to the speed and angle of Hight.

In order that the invention in its salient points may be readily understood, the accompanying drawing and the description predicated thereon are not complicated by provision for correction for windage or range or caliber or speed of projectile, mechanical means for adjusting the sights vertically for range and projectile speed and laterally for windage, being Well known and susceptible of embodiment herein by anyone skilled in gunnery; also while described as mounted for use on an anti-aircraft gun, the invention is obviously capable of employment in connection with semi-automatie-rriflemachine -gunsrand airplane guns used against other aircraft?" In the drawing:

Fig. 1 is a front elevation of a sight embodying the invention;

Fig. 2 is an edge elevation; and

Figs. 3 and 4 are detail sections on the lines 3-3 and 4 4 respectively of Fig. 1.

Describing the invention by reference to the drawing, the sight comprises a base plate 11 adapted to be iixedly mounted upon the gun in adjusted relation corrected for range, windage and other conditions. The upper portion 11a oi' the base plate 11 is annular in form and provided with an inwardly facing channel 12 within which is rotatably mounted a ring 13 upon anti-friction roller 5G bearings 14 conined between side plates 15.

At spaced points about the ring are provided studs or finger pieces 16 for manual rotation of the ring within the channel. A cro-ss hair or filament in the form of a thin wire 17 spans the ring diametrically, being firmly secured at its opposite ends to the ring for rotation with the latter to positions at varying angles to the horizontal.

Pivotally mounted upon the base plate at 18 is a cruciform frame consisting of intersecting arms 19, 20, 21 and 22, each of which radially extends from the pivot point 18. These arms may, as illustrated, comprise loops of stiff wire presenting an elongated open space axially of which extend hairs or filaments of wire 23, 24, 25 and 26.

The annulus 11a is graduated in terms of degrees from the horizontal upward and downward. The solid lower portion of the base plate 11 is provided with scales 27, 28, 29 and 30.

The scale 27 is graduated in terms of milesper-hour target speed in a horizontal direction. The scale 28 is graduated in terms of miles-per-hour of target speed at a left hand ascending angle to the horizontal. The scale 29 is graduated in miles-per-hour target speed at a right hand ascending angle to the horizontal. The scale 30 is graduated in terms of miles-per-hour target speed at right and left hand descending angles to the horizontal. Each of the scales 28, 29 and 8O comprises three sets of graduations, one relating to a 15, another 30 and the third 45 inclination to the horizontal, through an ascending angle as in scales 28 and 29, or a descending angle to the right or left as in the scale 30. Scale 27 being graduated for speed in the horizontal line, no angular correction is indicated.

It is to be-noted that these graduations representing target speed, as shown in the drawing, presuppose a multiplication by ten; that is to say, 8 should be read as 80, 12 as 120, 20 as 200, etc. This is done to facilitate reading of the drawing, although in actual practice the readings would probably be completed by the addition of the other digit.

The rear sight of my invention is usable as follows. Assume the target to be traveling in a horizontal direction, and the sight to have been adjusted for windage and range, the frame will be moved upon its pivot to bring the filament 25 to the graduation on the scale 27 representing the estimated speed of the plane, say 150 miles per h'our. This will swing the filament 23 to the right to a point of intersection with the filament 17 at the point 31 as indicated by a broken line. The alignment of the point 31 with the front sight of the gun will bring the latter to bear sufliciently in advance of the plane as to effect a hit when the projectile and the target simultaneously reach the point 31.

If, on the other hand, the target be moving to the right at an ascending angle to the horizontal, the gunner, by means of a stud 16 will rotate the ring 13 to bring the filament 17 into parallelism with the line of flight of the target. Assume the target be found to be traveling to the right at an ascending angle of 15 to the horizontal as indicated on the annulus 11a, the cruciform frame will likewise be swung to the right until the filament 24 is brought to the estimated speed of 150 miles per hour on the scale representing 15 right climb, whereupon the filaments 17 and 23 will intersect at the point 32, as indicated by dot and dash lines, above the horizontal and sufficiently in advance of the moving target that an alignment of the intersection point 32 and the front sight will cause the projectile and target to reach said point 32 simultaneously, effecting a hit.

To illustrate further, if the target be diving to the leftl at a speed of 150 miles per hour, the filament 17 will be shifted into parallelism with the line of flight. At the angle of dive indicated on the annulus 11a as 30, the frame will be shifted towards the left and the filament 25 caused to traverse the scale representing 30 left dive, bringing the point of intersection of the filaments 17 and 23 to the point 33, as indicated by dash and double dot lines. This point of intersection brought into alignment with the front sight and target represents the point at which the target and the projectile will meet under the conditions stated.

It will thus be observed that I have provided for leading a moving target the proper distance whether traveling in a horizontal direction or at an ascending angle right or left or at a descending angle right or left. Obviously the functioning of the sight provides for leading the target properly whether the line of flight be at right angles to the straight-away or away from or towards the gunner, the speed of the target for which the scales are graduated representing apparent speed rather than actual speed. The essential principal of the invention may be utilized in connection with other refinements' of calibration and graduations as may be desired to take care of other conditions.

I claim:

1. A gun sight for use against moving targets, comprising two filaments normally disposed in right angular intersecting relation, one filament angularly adjustable about a pivot remote from the point of normal intersection to vary the angle and place of intersection, a scale graduated in terms of target speed, and a pointer movable with said adjustable filament and adapted to traverse the scale whereby to alter the location of the point of intersection of the filaments to accorl with the target speed to effect proper lea 2. A gun sight for use against moving targets, comprising two filaments normally disposed in right angular intersecting relation, one filament angularly adjustable about a pivot remote from the point of normal intersection to vary the angle and place of inl tersection, a second filament angularly adjustable about the point of normal intersection as a pivot to parallelism with the direction of flight, a scale graduated in terms of target speed and terms of right and left inclination of the line of fiight to the horizontal, and a pointer moving with the first filament and adapted to traverse the scale whereby to alter the location of the point of intersection of the filaments to accord with the g target speed and angle of climb or dive to effect proper lead.

3. A rear gun sight for use against moving targets, comprising a normally vertical filament adjustable relative to the vertical, a second normally horizontal filament adjustable relative to the horizontal, the two filaments intersecting as viewed axially of the gun, a fixed scale graduated in terms of target speed, and a pointer moving with the first filament and adapted to traverse the scale whereby to alter the location of the point of intersection of the filaments to accord with the target speed to eect proper lead.

l. A rear gun sight for use against moving targets, comprising a filament adjustable relative to the vertical about a fixed point, a second filament adjustable relative to the horizontal about a fixed point, the two filaments in intersecting relation as viewed axially of the gun, a scale graduated in terms of target speed and degrees of right and left inclination to the horizontal, and a pointer moving with the first filament and adapted to traverse the scale whereby to alter the location of the point of intersection of the filaments to accord with the target speed and angle of climb or dive to effect proper lead.

`5. A rear gun sight for use against moving targets, comprising a filament adjustable relative to the vertical about a fixed pivot point, a second filament adjustable relative to the horizontal about a fixed pivot point intermediate its length, the two filaments in intersecting relation as viewed axially of the gun, fixed scales graduated in terms of target speed and related to horizontal flight and right and left hand ascending and descending degrees of inclination to the horizontal, and a pointer moving with the first filament and adapted to traverse any one of the scales whereby to alter the location of the point of intersection of the filaments to accord with the target speed and angle of climb or dive to eiect proper lead.

6. A rear gun sight for use against moving targets, comprising a base plate mounted on the gun, a frame pivoted to the plate and supporting a filament adjustable about the pivot, a ring mounted for rotation about its center and carried by the upper portion of the base plate, a filament arranged diametrically of the ring and intersecting the filament of said frame as viewed through said ring, a pointer carried by the frame and eX- tending in a radial direction from its pivot point, the upper portion of the base plate around the ring graduated in terms of degrees about the center of the ring, the lower portion ofthe base plate carrying scales graduated in terms of target speed and related to horizontal flight and right and left hand ascending and descending degrees of inclination to the horizontal, said scales adapted to be traversed by the pointer whereby to alter the location of the point of intersection of the filaments to accord with the target speed and angle of climb or dive to effect proper lead.

7 A rear gun sight for use against moving targets, comprising a base plate mounted on the gun, a cruciform frame pivoted to the plate and supporting a pair of filaments adjustable relative to the vertical about the pivot, and a pair of filaments adjustable relative to the horizontal about said pivot, a ring mounted for rotation about its center and carried by the upper portion of the base plate, a filament arranged diametrically of the ring, the upper portion of the base plate around the ring graduated in terms of degrees from the horizontal about the center of the ring, the lower portion of the base plate carrying a pair of scales for traverse by a vertical filament and graduated one in terms of right and left horizontal target speed related to horizontal flight and the other in terms of right and left target speed related to different descending angles to the horizontal, another pair of scales for traverse by the horizontal filaments and graduated respectively in terms of target speed related to different ascending angles to the horizontal whereby to alter the location of the point of intersection of the filaments to accord with the target speed and angle of climb or dive to effect proper lead.

In testimony whereof I have hereunto subscribed my name.

WILLIAM T. RICKARDS. 

